Ventilating of lamp houses



Nov. s, 1938. WOOD 2,135,996

VENTILATING OF LAMP HOUSES Filed Aug. 11, 1936 DonakiLWooeL,

INVENTOR:

BY 4W.//

' ATTORNEYS.

Patented Nov. 8, 1938 UNITED STATES VENTILATING OF LAMP HOUSES Donald L. Wood, Rochester, N.

Y., assignor, by

mesne assignments, to Eastman Kodak Company, Jersey City, N. Jersey J., a corporation of New Application August 11, 1936, Serial No. 95,379

4 Claims.

This invention relates to motion picture projectoraand more particularly to the cooling and ventilating of the lamphouse thereof.

One object of the invention is to provide a new and improved lamphouse arrangement in which the heat radiated by the lamp filament is readily and effectively removed from the lamphouse. Another object is to provide such a lamphouse in which the lamp holding or supporting member is exterior of the lamphouse so as not to interfere with the free flow of cooling air therethrough. 'A further object is to provide a lamphouse of this class in which the hottest portion of the lamp is in the section of highest air velocity so as to be effectively cooled thereby. Still another object is to provide such a lamphouse in in which the streams of cooling air fiow in the same direction as the natural air movement, thus effectively cooling the lamphous and ventilating the same. A still further object is to provide such a lamphouse arrangement which is simple in construction, relatively inexpensive to manufacture, and highly effective when used.

To these and other ends the invention resides in certain improvements and combinations of parts, as will be hereafter more fully described, the novel features to be pointed out in the claims at the end of the specification.

In the drawing:

Figure 1 is a side elevation of a motion picture projector equipped with a lamphouse constructed in accordance with the preferred embodiment of the invention.

Figure 2 is a side elevation of the preferred type of lamphouse.

Figure 3 is a vertical sectional view of the lamphouse taken substantially of the line 33 of Figure 2.

Similar reference numerals throughout the several views indicate the same parts.

A lamphouse constructed in accordance with thepresent invention is herein illustrated as applied to a motion picture projector having a base Ii which supports a motor housing l2. the film operating mechanism which is enclosed in a suitable housing It positioned above the motor housing i2, and a chamber it in which the'lamphouse, generally indicated by the numeral I! and hereinafter more fully described, is positioned.

The operating mechanism may be of theusual and well-known construction driven by power through a motor positioned in the housing i2,

and consisting of a pull-down claw, not shown,

for intermittently moving a film 20 past a film gate through which light may pass. The film 20 is looped at 2i and 22 on'opposite sides of the film gate, and is fed to the'loop 2i by means of a continually rotating sprocket 28, which draws the film 20 from a supply reel 25, rotatably mounted on the spindle 26 carried by the up- 5 wardly projecting arm 21.

A second sprocket 30, similar to the sprocket 23, moves the film 20 from the loop 22 to a takeup reel 35 rotatably-mounted on a'spindle 36 carried by the arm 31. The take up reel is operated 10 by means of a power driven belt 38 which is connected to a motor, not shown, positioned within a housing i2, as is well known.

The above described mechanism, with the exception of the lamphouse it, may be of the usual 15 or any construction well-known to those in the art, and does not constitute a part of the present invention.

Referring now to Figures 2 and 3"wherein is shown a lamphouse l5 constructed in accordance 20 with the preferred embodiment of the invention. This lamphouse comprises, in general, a substantially vertical tubular member of fluid conduit having an enlarged lower end 40 which forms a fan casing or scroll, an intermediate con- 25 verging section 42, and a fiared out discharge opening 43, all will be hereinafter more fully described: It is apparent from an inspection of Figure 3 that the upper portion of the lamphouse constitutes a substantial Venturi nozzle of 30 which the converging section 42 is the throat thereof.

The throat 42 is formed with laterally extending tubular sleeves l5 and 46 which are in optical alignment with the front lens barrel 48 of the as projector; and in which are respectively mounted, in the manner shown, a reflector 50, and a rear lens barrel ii in which are suitably secured the lenses 52. The reflector I0 and the lenses 52 provide means for directing light rays from a 40 source of illumination, such as the lamp 55, through an image on a film 20, and then through suitable lenses in the front barrel 48 to an image receiving screen. 7

When a high intensity source of illumination 45 such, for example, as the electric lamp 5!, is used, a large amount of heat is radiated into the lamphouse. In order to protect the various parts of the projector, it is highly essential that this heat be readily and effectively carried away or 50 dissipated as fast as radiated, for obvious reasons. Such heat is usually carried away by means of a stream of cooling air which flows through the lamphouse and over the lamp itself to cool the latter'and to remove the heat radiated thereby. 55

It is well known, however, that the most effective air cooling is secured when the coolest air is directed into intimate contact with the hottest portion of the object'tc be cooled; and when the free passage of the air over the object is not obstructed nor deflected by various objects such, for example, as the lamp supporting socket or base.

In prior lamp lamphouse constructions, the cooling air first contacts the base of the lamp, and, after being somewhat raised in temperature, it finally reaches the hot filament area of the lamp. Furthermore, the lamp socket is usually positioned directly in the path of the flowing air, and thus deflects the latter so as to cause eddy current, thus not only materially reducing the cooling effect of the air, but also decreasing the fan efficiency.

The present invention overcomes these objectionable features by placing the lamp supporting socket outside of the lamphouse proper, and by inverting the lamp within the lamphouse so that the lamp extends directly into the path of the cooling air, thus bringing the hot filament area of the lamp into the direct path of the coldest air, as will be apparent from inspection of Figures 2 and 3.

In the specific embodiment of the invention, the lamp 55 extends downwardly through the flared-out discharge opening 43, and has the axis thereof in substantial alignment with the vertical axis of the Venturi nozzle. The filament area 55 of the lamp is arranged within the converging section on throat 42 of the lamphouse, and in alignment with the optical axis of the reflector 50 and the lenses 52. The lamp is connected to and supported by a suitable receptacle or socket 60, which is arranged above and exteriorally of the lamp house and out of the direct path of the streams of cooling air flowing through the lamphouse, as will be apparent from an inspection of Fig. 3.

In the preferred embodiment, the socket is preferably mounted on and supported by an L- shaped bracket 6|, the shorter leg 52 of which is secured by rivets or other fastening means 63 to the door 64 0f the chamber l4. The door 64 is hingedly connected along the line 65 to the lamphouse, so that the door may be swung to open position to permit removal and replacement of the lamp 55, as well as cleaning of the optical members 50 and 52, all as will hereinafter be more fully described. The socket 55 is connected to a suitable source of electrical current, not shown, by which the lamp filament 56 may be illuminated to project the image on the film 20, as is well known to those of the art.

A continuous supply of cooling air is provided by a fan 58 rotatably mounted on a shaft 59 in the fan casing 40. This fan forces streams of cooling air upwardly through the lamphouse and over the lamp 55 to effectively cool the latter, as well as. the adjacent optical members. This fan is operatively connected to and driven by a motor within the housing i2. Air is admitted to the fan through grilles 10 at the bottom of the chamber l4 as clearly illustrated in Figure 1.

Referring now to Figure 3, it is apparent that when the lamp is inverted so as to extend downwardly into the lamphouse, the cooling air first engages the hot filament area 55 of the lamp. It is also apparent that by placing the light supporting socket 60 outside of the lamphouse, no obstructions are present in the path of the air, so that the latter may travel in substantially streamline relation through the entire lamphouse to cool and ventilate the latter. -By reason of this stream-line fiow, not only is more effective cooling secured, but the fan efficiency is also thereby increased.

As pointed out above, the upper portion of the lamphouse is in the form of a Venturi nozzle, section 42 of which constitutes a Venturi throat. Such a throat provides a means for converting a portion of the static head of the air leaving the fan into velocity head so that the velocity of the air streams passing through the throat 42 is thereby greatly increased. As the filament area 55 of the lamp is substantially concentrically positioned within the throat 42, it is obvious that the high velocity air streams will readily and efiectively carry away the heat radiated by the lamp filament. The static head of the air is substantially restored by reason of the fiared out discharge opening 43, as is well known by those familiar with the art.

The entire lamphouse l5 may be suitably secured in vertical position within the chamber l4, in any well-known manner. To permit replacement of the lamp 55, as well as the cleaning of the optical members 50 and 52, a portion of the lamphouse i5 is preferably secured to and movable with the door 64. In the present embodiment, the lamphouse is split along the line 50 to form a narrow side portion ll, see Figure 2, which is rigidly secured to and movable as a unit with the door 64. Rivets or other securing means are provided for mounting the portion 8| on the door 54, as clearly illustrated in Figs. 1 and 2.

It is also apparent from an inspection of Figure 2, that when the door 64 is swung open, the lamp 55 as well as the portion ll are moved into the position shown by the dotted line, thus facilitating the replacing of the lamp 55 and/or the cleaning of the optical members 50 and 52. When, however, the door is closed, as shown in full line, the portion ll abuts the lamphouse l5 along the line III to forman air tight connection therewith. A small knob 85 permits easy opening of the door.

It is apparent from the above description that by inverting the lamp 55, not only are obstructions entirely eliminated within the lamphouse so that the air can pass therethrough in definite stream-lines; but also the coolest air first engages the hottest portion of the lamp, thus insuring the maximum cooling effect. Furthermore, the movement of the cooling air is in the direction of the natural air movement through the lamphouse thus assisting in the proper ventilation of the latter.

While one embodiment of the invention has been disclosed, this is by way of illustration only, as it is understood that the inventive idea may be carried out in a number of ways. This application is, therefore, not to be limited to the precise details disclosed, but is intended to cover all modifications and variations thereof falling within the spirit of the invention and the scope of the appended claims.

I claim:

1. In a motion picture projector, the combination with a chamber, of a lamphouse positioned within said chamber and comprising a fiuid conduit, means for forcing strea of cooling fiuid upwardly through said condfi, a door operatively connected to said chamber, a lamp supported on said chamber and inverted within said conduit and in the path of said streams so as to be cooled thereby, and a part or said conduit adjacent said lamp secured to' and movable as a unit with said door to facilitate replacement or said lamp.

2. In a motion picture projector, the combination with a chamber, of a lamphouse positioned within said chamber and comprising a fluid conduit, means for forcing streams of cooling fluid upwardly through said conduit, a door hingedly connected to said chamber, a lamp inverted within said conduit and in the path of said streams so as to be cooled thereby, lamp supporting means mounted on said door, and a portion 01' said conduit adjacent said supporting means mounted on and movable with said door to facilitate replacement of said lamp.

3. In a motion picture projector, the combination with a chamber, of a lamphouse positioned within said chamber and comprising a fluid conduit, a converging portion between the ends of said conduit to form a Venturi nozzle having a throat, a fan for forcing streams of cooling air through said nozzle, said throat providing a section'of high velocity streams, a door hingedly connected to said chamber, an inverted lamp including a filament area mounted on said door exteriorly of said conduit and extending downwardly into said nozzle and with the filament area thereof in said throat whereby said area is cooled by said high velocity streams, and a part of said conduit adjacent said throat secured to and movable with said door to facilitate the replacement of said lamp.

4. In a motion picture projector, the combination with a chamber, of a lamphouse within said chamber and comprising a stream-line fluid passageway, a lamp within said lamphouse and positioned in said passageway and including a filament which heats a portion 'of said lamp to a high temperature, a restricted area in said passageway surrounding the filament section of said lamp, a fan rotatably mounted in said lamphouse to force streams of air through said passageway, a door operatively connected to said chamber, and lamp supporting means mounted on said door and movable therewith to move said lamp into and out of projecting position.

DONALD L. WOOD. 

